JP2012112017A - Titanium alloy sheet for drum for producing electrolytic copper foil with sheet surface texture developed, and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a titanium material for a drum for producing copper foil having a uniform and fine sheet surface metal texture with no defect with a diameter of several tens μm or less caused by plucking in polishing, and manufacturable without depending on complicated thermomechanical treatment, and a method for manufacturing the titanium material.SOLUTION: A titanium sheet for the drum for producing electrolytic Cu foil contains, by mass%, 0.3-1.1% Cu, at most 0.04% Fe, at most 0.1% oxygen, and at most 0.006% hydrogen, and has an average crystal grain size of 8.2 or more, and a Vickers hardness of 115 or more and 145 or less. At a portion parallel with a sheet surface, the texture has an area ratio A/B of 3.0 or more, wherein A is the total area of crystal grains existing within an elliptic range in which a fall angle of a normal of a (0001) plane being ±45° in a direction of a rolling width direction TD is set as a major axis and the fall angle being ±25° in a direction of a final rolling direction RD is set as a minor axis in a (0001) plane pole figure of an α phase from a normal line (an ND axis) from a rolling face, and B is the total area of other crystal grains.

Description

  The present invention is a drum titanium material for producing a copper foil (referred to as Cu foil) used for a multilayer wiring board of an electronic component, a flexible wiring board, a negative electrode current collector of a lithium ion battery, etc. In addition, the present invention relates to a material having a dense plate surface metallographic structure and a manufacturing method thereof.

  Cu foil used for these applications is a copper sulfate solution in which a Cu raw material is dissolved in a sulfuric acid solution. An insoluble metal such as Pb or titanium is used as an anode, and a drum having a width of 1 m or more and a diameter of several meters is used as a cathode. It is manufactured by a method in which Cu is continuously electrodeposited on a drum while being rotated, and this is continuously peeled off and wound into a roll. As a material for the drum, titanium is used from the viewpoints of excellent corrosion resistance and excellent peelability of the Cu foil.

  However, even a highly corrosion-resistant titanium material is gradually corroded in the electrolyte during use, and the newly appearing surface state is transferred to the Cu foil. It is known that the degree of metal corrosion varies depending on various internal factors such as the structure, crystal orientation, defects, segregation, processing strain and residual strain of the metal material. If a drum made of an internal material is corroded during use, a uniform surface state cannot always be maintained.

  Among such heterogeneous tissues, those that can be discriminated with the naked eye are called “macro patterns”. In the case of a titanium drum for producing copper foil, the surface of the macrostructure is polished with sandpaper No. 600 and immersed in an etching solution of about 10% nitric acid, about 5% hydrofluoric acid and the remaining water for several tens of seconds to several minutes. Can be obtained. For some reason, if there is an inhomogeneous structure even several millimeters in length, these portions are different from each other in the etching state, and thus are discriminated with the naked eye. Therefore, homogenizing the macro structure of the raw material titanium material, that is, reducing the so-called “macro pattern” that occurs in the macro structure, achieves uniform corrosion of the drum, and highly accurate and uniform thickness Cu foil. Is essential for manufacturing.

  On the other hand, in Patent Document 1, a titanium material is heated to 950 ° C. or higher and rough-rolled, and then heated to a temperature of 700 ° C. or lower, and then finish rolling is cross-rolled in a direction perpendicular to the direction of rough rolling. A method is described.

  In Patent Document 2, in the surface layer portion parallel to the plate surface extending from the outermost surface to 1/3 plate thickness, the average particle size is 40 μm or less, and the texture is [0001] 0 ° to ± 45 ° TD, and , [0001] 0 ° to ± 25 ° RD (where TD is the sheet width direction and RD is the rolling direction), titanium for a pure titanium copper foil manufacturing drum excellent in surface layer structure has been proposed Yes.

  Patent Document 3 discloses a titanium material for producing an electrolytic copper foil characterized by having a crystal grain size of 7.0 or more and an initial hydrogen content of 35 ppm or less, and a rolling start temperature of 200 ° C. A method has been proposed in which rolling is performed at a rolling reduction temperature of less than 550 ° C., a rolling end temperature of 200 ° C. or more, and a rolling reduction of 40% or more.

  Patent Document 4 discloses a titanium for copper foil manufacturing drum containing Cu in a mass% of 0.15% or more and less than 0.5%, and Patent Document 5 includes Cu in a range of 0.5% or more and 2.1% or less. Proposed.

Japanese Patent Laid-Open No. 60-9866 JP 2002-285267 A JP 2002-194585 A JP 2009-41064 A Japanese Patent Laid-Open No. 2005-298753

  In recent years, the surface quality of copper foil used in electronic components has become more severe as the copper foil becomes thinner, and not only the “macro pattern” that can be discerned with the naked eye, but also the wrinkles on the surface during polishing. ) Micro-sized defects having a diameter of several tens of μm or less due to unevenness of the case have become a problem. The curvature of the surface of the titanium drum material refers to the portion shown in FIG.

  The method disclosed in Patent Document 1 suppresses the appearance of macro patterns due to coarse crystal grains by lowering the heating temperature in finish hot rolling, and performs cross rolling in a direction perpendicular to the direction of rough rolling. By doing so, the band-like macro pattern generated in the rolling direction is suppressed, but the appearance of the micro-sized defects cannot be suppressed.

  In Patent Document 2, in pure titanium, rapid cooling after forging in the β temperature range, rough rolling in the α temperature range, and finish rolling at a temperature of 650 to 750 ° C. in a direction perpendicular to the direction of the rough rolling. By rolling, annealing, cold rolling, and re-annealing, a characteristic texture is obtained, and a pure titanium material for a copper foil production drum without a macro uneven pattern is obtained. However, this method has complicated processes and complicated manufacturing condition management. In addition, the texture is such that the [0001] axis is almost parallel to the plate normal direction (tilt is within 25 °), Center-Pole-texture, and the [0001] axis is tilted 35 to 45 ° in the plate width direction. A TD-texture and [0001] axis is a split-RD-texture single or composite texture in which the axis is inclined by 35 to 45 ° in the plate width direction. However, in the as-rolled material, the [0001] axis is tilted by 70 ° or more in the plate width direction, and the ratio of the total crystal grains is also present in the transverse direction. -texture may not be sufficiently suppressed, and in that case, there is a part where the crystal orientation of adjacent crystal grains is significantly different. In some cases, it was insufficient in quality as a drum material for producing high-quality copper foils that do not require size wrinkles. Further, the patent document states that “the texture is [0001] 0 ° to ± 45 ° TD and [0001] 0 ° to ± 25 ° RD (where TD is the sheet width direction and RD is the rolling direction). There is a problem that does not quantitatively describe the characteristics of the texture.

  In Patent Document 3, as a titanium material for producing an electrolytic copper foil characterized by having an average grain size of 7.0 or more and an initial hydrogen content of 35 ppm or less, a rolling start temperature is 200 ° C. or more and 550 ° C. A method has been proposed in which rolling is performed at a temperature below 200 ° C. and a rolling end temperature of 200 ° C. or more and a reduction rate of 40% or more. A pure titanium material having a crystal grain size of 7.0 or more and a hydrogen content of 35 ppm or less is a pure titanium product. In this case, the crystal grain size and the hydrogen content are extremely normal, and micro-sized defects cannot be suppressed only by suppressing the formation of hydride by reducing the structure to this extent and suppressing the hydrogen content.

  In Patent Document 4, Cu is 0.15% or more and less than 0.5% by mass, and Patent Document 5 includes titanium for a copper foil manufacturing drum containing Cu in an amount of 0.5% or more and 2.1% or less, and , Heated to α + β two-phase temperature range, hot-rolled, annealed at a temperature range of 500 ° C. to β transformation point, further cold-rolled, and annealed at a temperature range of 500 ° C. to β transformation point A manufacturing method has been proposed, but this method has complicated processes and complicated manufacturing condition management. In addition, the suppression of micro-sized defects is insufficient.

  In view of the present situation as described above, the present invention is a titanium material for a copper foil manufacturing drum, which is not only a macro pattern but also a micro-size defect caused by wrinkling during polishing; It is intended to provide a titanium material for a drum having a fine plate surface metallographic structure, which can be manufactured without relying on complicated processing heat treatment, and capable of manufacturing high-quality electrolytic Cu foil, and a manufacturing method thereof. is there.

  As a result of investigating the relationship between the surface crystal orientation of the Cu-added titanium alloy, the surface wrinkling state during polishing, and the occurrence of micro-sized defects, the present inventors have made extensive studies on the manufacturing method. We found a texture that can suppress not only patterns but also micro-sized defects, and found the manufacturing process.

The present invention has been completed based on such findings, and the gist thereof is as follows.
(1) By mass%, Cu: 0.3-1.1%, Fe: 0.04% or less, Oxygen: 0.1% or less, Hydrogen: 0.006% or less, from the remaining titanium and inevitable impurities The average grain size is 8.2 or more and the Vickers hardness is 115 or more and 145 or less in a portion parallel to the plate surface of 1.0 mm below the surface and 1/2 plate thickness part, and the final rolling direction RD , Rolling surface normal ND, rolling width direction TD, (0001) surface normal is c-axis, 1.0 mm below the surface and the part parallel to the plate surface of the 1/2 plate thickness part In the (0001) plane pole figure of the α phase from the normal direction to the rolling surface, the inclination angle of the c-axis is a long axis of ± 45 ° in the TD direction in a wolf net centered on the ND axis. The total area of crystal grains in the range of an ellipse having a minor axis of ± 25 ° in the RD direction A titanium plate for an electrolytic Cu foil production drum, wherein the total area of A and other crystal grains is B, and the area ratio A / B is 3.0 or more.
(2) A manufacturing method for obtaining a titanium material by finish rolling through a hot rolling step by α + β two-phase region heating, wherein the finish rolling step has a rolling start temperature of the titanium material of 200 ° C. or more and 700 ° C. or less. The titanium material is rolled at a rolling reduction of 40% or more, and finally subjected to a heat treatment at 550 to 700 ° C. for 10 to 30 minutes, The method for producing a titanium plate for an electrolytic Cu foil production drum according to (1) .

  According to the present invention, a titanium plate for an electrolytic Cu foil production drum having a uniform and fine plate surface metal structure with few micro-size defects and suitable for producing a high quality electrolytic Cu foil and a method for producing the same are provided. It can be provided without going through a special heat treatment process.

Photomicrograph showing the wrinkles that occurred on the surface of the titanium material Schematic diagram showing an elliptical region having a major axis of ± 45 ° in the TD direction and a minor axis of ± 25 ° in the RD direction in a wolf net centered on the ND axis. Example of (0001) pole figure in EBSP crystal orientation analysis

  In the titanium plate of the present invention, Cu: 0.3 to 1.1%, Fe: 0.04% or less, oxygen: 0.1% or less, hydrogen: 0.006% or less, and the remaining titanium and unavoidable. It was made of impurities.

  First, the reason why each composition is limited to the above range will be described.

  The titanium alloy containing Cu in the Cu concentration range (0.3 to 1.1%) of the present invention has a wide temperature range of 840 to 870 ° C., which is a two-phase α + β phase. Thus, by using such a titanium material and heating to α + β two-phase temperature range and hot rolling, crystal grain growth is remarkably suppressed as compared with a single-phase structure, so that a finer structure is obtained. The processed recrystallized structure becomes more homogeneous and finer as the structure before processing becomes finer. Moreover, Vickers hardness can be raised as a result of refinement | miniaturization of crystal structure.

  In the present invention, the titanium alloy containing the above Cu amount is hot-rolled in the α + β two-phase temperature range, and then subjected to finish rolling and heat treatment shown in the method for producing a titanium plate of the present invention, whereby the final rolling direction RD, rolling When the surface normal ND, the rolling width direction is TD, and the (0001) surface normal is the c-axis, the texture is 1.0 mm below the surface and parallel to the plate surface of the 1/2 plate thickness part. In the (0001) plane pole figure of the α phase from the normal direction to the rolling surface, the c-axis is a wolf net centered on the ND axis, the major axis is ± 45 ° in the TD direction, and ± 25 ° in the RD direction. The total area of crystal grains existing in the elliptical region with A as the short axis can be A, the total area of other crystal grains can be B, and the area ratio A / B can be 3.0 or more. In the wolf net centered on the ND axis, an elliptical region having a major axis of ± 45 ° in the TD direction and a minor axis of ± 25 ° in the RD direction is the part of the ellipse shown in the schematic diagram of FIG. . A wolf net is a curve in which a grid of latitude and meridian lines is placed on a hemisphere and these are stereo-projected onto a disk (FIG. 2).

  Thus, the α + β two-phase region rolling produces fine crystals having an average crystal grain size of 8.2 or more, and the c-axis of most crystal grains having an area ratio A / B of 3.0 or more is relative to the plate surface. Vickers hardness due to the synergistic effect of having a texture that is nearly vertical (normal to the normal line ND direction of the rolling surface), and finally a macro-inhomogeneous structure and a homogeneous fine crystal structure with no micro-size defects. Is a technique that can achieve a high hardness of 115 to 145, and obtain a micro-size defect during polishing and a structure in which surface wrinkles that cause the defect are minute or difficult to occur.

In order to realize this, the amount of Cu needs to be 0.3 to 1.1%. When Cu is less than 0.3%, it is difficult to set the average grain size to 8.2 or more even if two-phase rolling is performed, so the lower limit of the Cu amount is set to 0.3%. Further, if it exceeds 1.1%, Ti ₂ Cu is likely to precipitate during finish rolling, and a macro nonuniform pattern may occur.

  The reason why Fe, oxygen, and hydrogen are limited to the scope of the present invention will be described.

  Fe is an element that stabilizes the β phase, and the amount of solid solution in the α phase is extremely small and is 0.04% at most even at the temperature at which the most solid solution is formed. When Fe is added in excess of this, a β-phase enriched with Fe appears, but this β-phase is preferentially dissolved in a corrosive environment and tends to be a pit-like depression. If such a dent exists on the surface, it is transferred to the Cu foil to be electrodeposited, so that a high-quality Cu foil cannot be produced. Therefore, the Fe content needs to be 0.04% or less. The lower limit of the amount of Fe is not particularly specified, but is usually 0.005% or more as an impurity.

  Pure titanium and main titanium alloys have an α phase of hcp structure as the main phase, and oxygen is an alloying element that strengthens this. Since the electrolytic Cu foil production drum is formed into a cylindrical drum by bending the plate cold, the softer one is easier to mold, and the residual stress after molding is smaller and uniform. This residual stress also contributes to the generation of the macro pattern, and in order to reduce this, the oxygen content is set to 0.1% or less in the present invention. The lower limit of the amount of oxygen is not particularly specified, but is usually 0.005% or more as an impurity.

  The reason why H is set to 0.006% or less is to suppress the formation of hydride. When hydride is generated, impact characteristics deteriorate, and there is a possibility that it may cause trouble during processing and handling. If the H concentration is 0.006% or less, hydride is hardly generated in a material having an average crystal grain size of 8.2 or more, so the upper limit was made 0.006%. The lower limit is better from the point of not generating hydride, but usually 0.001% or more is often contained as an impurity. The inevitable impurities refer to impurity elements that are unavoidable to be mixed into the material in the manufacturing process such as refining and melting. For example, 0.05% or less of nitrogen, carbon, hydrogen, Ni, Cr, It refers to Mn, Mg, Sn, Al, V, Si and the like.

  In order to control the contents of Fe, oxygen, and hydrogen within the ranges described above, high-purity sponge titanium is used as a titanium raw material, and the use ratio of scrap titanium may be adjusted. Furthermore, the hydrogen content can be controlled by adjusting the atmosphere by supplying a trace amount of excess oxygen to the atmosphere during heating.

  Further, in the present invention, when the final rolling direction RD, the normal line ND of the rolled surface, the rolled width direction TD, and the normal line of the (0001) plane are c-axis, 1.0 mm below the surface and 1/2 plate thickness part In the part parallel to the plate surface, the texture is a (0001) plane pole figure of the α phase from the normal direction to the rolling surface, and the tilt angle of the c-axis is a Wolfnet centered on the ND axis. The total area of crystal grains existing within an ellipse with ± 45 ° as the major axis in the TD direction and ± 25 ° as the minor axis in the RD direction is A, and B is the total area of the other crystal grains. It was set as the titanium plate for electrolytic Cu foil manufacture drums characterized by A / B being 3.0 or more. The reason why the texture is defined as described above is to obtain the following effects in addition to the effect of increasing the hardness of the titanium plate as described above.

  Titanium materials for copper foil production drums have so far been mainly related to macro non-uniform patterns, but the macro non-uniform patterns can be easily identified with the naked eye and are several millimeters in size. Surface defects, which are caused by residual coarse grains or streak-like rolled microstructures remaining during hot rolling, so that cross rolling during hot rolling and the amount of processing in the α temperature range can be reduced. It was solved by taking enough.

  On the other hand, micro-sized defects having a diameter of several tens of μm or less are related to the orientation of adjacent crystal grains. Each crystal grain of the α-type titanium material has an HCP structure, but since the bottom surface (0001) surface of HCP is the most dense, the hardness is higher than the column surface (10-10) surface, and depending on the polishing conditions, The way the surface is beaten is different. Therefore, if these faces exist adjacent to each other, one of them will not be scratched very much, and one of them will be scratched remarkably, so the difference in the boundary will be significant, and the micro size will be several tens of μm (size equivalent to the crystal grain size) or less. It will be recognized as a defect. Even if the crystal grains of the drum material are completely random, such a combination occurs somewhere, so that a defect is locally generated. In view of such facts, the inventors have found that defects at the time of polishing can be suppressed if most of the crystal grains are aligned on the bottom (0001) plane or a plane with an orientation close thereto.

  That is, when the final rolling direction RD, the normal ND of the rolled surface, the rolling width direction TD, and the normal of the (0001) plane as the c axis, the (0001) plane pole of the α phase from the normal direction to the rolled surface In the figure, the total area of the crystal grains in which the c-axis is present in an elliptical region having a major axis of ± 45 ° in the TD direction and a minor axis of ± 25 ° in the RD direction of the wolf net centered on the ND axis is represented by A The texture is characterized in that the total area of other crystal grains is B and the area ratio A / B is 3.0 or more.

  The c-axis of the titanium material is more inclined in the TD direction than in the RD direction. The inclination angle of the c-axis in the TD direction was ± 45 °. The reason why the upper limit is set to 45 ° is that, if the upper limit is exceeded, the difference in hardness from the crystal grain surface at an angle of 0 ° becomes remarkable, so that the difference in wrinkling during polishing increases. The tilt angle of the c-axis in the RD direction is ± 25 °. Since the c-axis is not tilted in the RD direction as compared with the TD direction, the upper limit is set to 25 °.

  In the present invention, the total area A of the crystal grains in which the c-axis exists in an elliptical region having a major axis of ± 45 ° in the TD direction and a minor axis of ± 25 ° in the RD direction of the wolf net centered on the ND axis. The total area B and the area ratio A / B of other crystal grains are calculated as follows.

  First, the observation surface of the sample is chemically polished, and crystal orientation analysis is performed using an electron backscattering diffraction pattern (EBSP). An area of 1 mm × 1 mm is scanned in steps 1 to 2 μm, and a (0001) pole figure (FIG. 3) is drawn. A black dot in the figure indicates an angle at which the normal line of the (0001) plane, that is, the c-axis is inclined with respect to the normal line of the plate surface (ND axis). The angle can be read by overlapping the wolf net shown in FIG. The ratio of the density of black spots in the ellipse (b in FIG. 2) that is −45 to 45 ° in the TD direction and −25 to 25 ° in the RD direction and the density of black spots in the other part of the wolf net is This corresponds to the ratio A / B of the total area A of the crystal grains in the region where the c-axis is an ellipse b and the total area B of the crystal grains where the c-axis is in a portion other than the ellipse b. The density of black spots in the area of the ellipse b and other areas is obtained by reading each image analysis. A / B of 3.0 or more means that the c-axis of 75% or more of the crystal grains in the observation range is gathered in a region near the center. The reason for setting it to 3.0 or more is that when it is less than 3.0, the accumulation near the center is small, the number of crystal grains whose c-axis is tilted with respect to the plate surface increases, and wrinkling during polishing becomes remarkable. is there. The upper limit is the case where A is 100% and B is zero, but there is actually no such case and is 3.0 to 19.0. Further, it is preferable that A / B 3.0 or more is satisfied uniformly over a depth of ½ thickness from the surface. If the A / B on the surface of 1.0 mm to 1.0 mm and the surface of 1/2 thickness is 3.0 or more, the A / B is approximately 3.0 or more evenly from the surface to 1/2 thickness. It was confirmed.

  In the present invention, the average crystal grain size and hardness are 1.0 mm or less below the surface and the part parallel to the plate surface of the 1/2 plate thickness part has an average crystal grain size of 8.2 or more and a Vickers hardness of 115 or more. 145 or less. The reason why the average grain size is set to 8.2 or more is as follows. It is difficult to align the c-axis orientation of all the crystal grains substantially perpendicular to the plate surface, and there is a certain proportion of crystal grains in which the c-axis is tilted in the TD direction. In such a case, even if there is a place where the wrinkle at the time of polishing is different from the surroundings, if the crystal grains are fine, the region becomes narrower than the tens of μm level and becomes less conspicuous. Become. This effect is effective when the average grain size is 8.2 or more. If it is recrystallized, the finer the crystal grain, the better. However, it is desirable that the crystal grain is substantially in the range of 8.2 to 10.5. In addition, it is desirable that the surface has a certain degree of hardness in order to reduce wrinkles during polishing or to prevent wrinkles themselves from occurring. If the Vickers hardness is 115 or more, the wrinkles become minute and are less noticeable as defects. However, if it is too hard, polishing itself becomes difficult, so the upper limit was set to 145.

  Moreover, it is preferable that the conditions of the crystal grain size and the hardness are uniformly satisfied over a depth of ½ thickness from the surface. If the crystal grain size is in the range of 8.2 to 10.5 and the Vickers hardness is in the range of 115 to 145 on the surface of 1.0 mm to 1.0 mm and 1/2 thickness, even between the surface and 1/2 thickness It was confirmed that the crystal grain size was in the range of 8.2 to 10.5 and the Vickers hardness was in the range of 115 to 145.

  The method for producing a titanium plate for an electrolytic Cu foil production drum according to the present invention is a production method for obtaining a titanium material by finish rolling through a hot rolling step by α + β two-phase region heating. The heat treatment is performed at a temperature of from 700 ° C. to 700 ° C. and a rolling reduction of 40% or more, and finally a heat treatment is performed at 550 to 700 ° C. for 10 to 30 minutes.

  When a titanium material having the component composition of the present invention is heated in the α + β two-phase temperature range and immediately hot-rolled, Cu is contained in the range of the present invention, so that hot rolling is performed in a sufficient α + β two-phase temperature range. be able to. Since the α + β two-phase temperature range is 840 to 880 ° C., it is desirable that the heating temperature is 830 to 870 ° C. in consideration of processing heat generation. Thus, a homogeneous crystal structure can be obtained by performing hot rolling at an α + β two-phase region temperature. When hot rolling is performed in the α + β two-phase region, the α phase and the β phase interfere with each other's crystal grain growth, so that the crystal grain size can be prevented from becoming coarse. Thereafter, upon cooling, the β phase is transformed into an α phase, and as a result, an α single phase structure having a small average crystal grain size is obtained.

  Next, in finish rolling, rolling is performed at a rolling start temperature of 200 ° C. or higher and 700 ° C. or lower and a rolling reduction of 40% or higher. In finish rolling, by rolling at a temperature lower than the normal hot rolling temperature, it is possible to form a very strong texture defined in the present invention. At this time, when the temperature exceeds 700 ° C., the formation of the texture becomes insufficient. When the temperature is less than 200 ° C., wrinkles are liable to occur during rolling and the rolling shape is deteriorated.

  The rolling reduction during finish rolling was set to 40% or more. If the rolling reduction is less than 40%, the texture defined in the present invention is not sufficiently formed, and the risk of causing micro-sized defects due to wrinkling during polishing is increased.

  Further, after the finish rolling, the titanium material is heat-treated at 550 to 700 ° C. This is a process for obtaining a homogeneous fine recrystallized structure by accelerating recrystallization with a strain accumulated at a high temperature by finish rolling at 200 to 700 ° C. as a nucleus. Therefore, the lower limit of the annealing temperature is set to 700 ° C. in order to make the recrystallization temperature 550 ° C. and as fine a grain as possible, and the upper limit temperature to make the crystal grain size fine. If the retention time is 10 min or less, the in-plane uniform temperature distribution is not achieved, and the crystal grain size is mixed, which is not good. Further, if the holding time is 30 minutes or more, the surface oxidation becomes excessive, the load of the subsequent deoxidation film process becomes large, and the productivity is not preferable. For the above reasons, the final annealing condition after cold rolling is defined to be maintained for 10 to 30 minutes in a temperature range of 550 to 700 ° C.

  The present invention will be described in more detail with reference to examples.

  An ingot of 200 kg composed of the components shown in Table 1 was prepared by melting twice with a vacuum arc, and this was divided and rolled into a slab having a thickness of 150 mm. About this slab, the finish rolling was performed through the hot rolling process. Table 2 shows the heating temperature during hot rolling, the plate thickness after hot rolling, the start temperature of finish rolling, the plate thickness after finish rolling and the rolling reduction.

  The surface of these samples 1 mm below the surface layer and the surface of the 1/2 plate thickness portion was mechanically polished to a mirror surface, and then polished using colloidal silica. Then, crystal orientation analysis was performed using FE-SEM (Field Emission-Scanning Electron Microscope) / EBSP. For EBSP measurement, in order to obtain the average information of the sample, a range of 1 mm × 1 mm for each sample, 5 fields of view were measured at 2 μm, a (0001) pole figure was drawn, and a wolf centered on the ND axis. The density of black spots in an ellipse (b in FIG. 2) that is −45 to 45 ° in the TD direction and −25 to 25 ° in the RD direction and the density of black spots in other portions are obtained by image analysis. The ratio (A / B) was determined.

  In addition, a 50 mm x 70 mm test piece was cut out, 1 mm below the surface and 1/2 surface thickness were exposed by milling, polished with sandpaper polishing No. 600, and then combined with polyvinyl alcohol acetalized product. Polishing was performed with an elastic grindstone (abrasive grains were SiC, grain size # 600, hereinafter referred to as PVA grindstone), and the surface condition was observed by SEM observation. The lubricating oil used was petroleum. As for the surface state, the state of dripping after PVA polishing was observed. When the number of wrinkles generated in a 100 × 130 μm region was 5 or more, it was evaluated as “slightly”, when it was 2-4, “small”, and 1 or less were evaluated as “nearly absent”.

  The crystal grain size was measured in accordance with JISG0551 from the microstructure by observing the microstructure of each of five arbitrary locations on the surface of the surface layer of the small piece 1 mm below and the surface of the 1/2 plate thickness portion. Regarding Vickers hardness, the hardness of the same surface was measured at 5 points with a load of 1 kg and averaged.

  Table 2 summarizes the manufacturing conditions, the respective measured values, and the evaluation of wobbling during polishing.

  No. Examples 1 to 14 are examples of the present invention. The heating temperature of rough rolling is a temperature at which two phases of α + β are formed in each alloy composition. Since the plate thickness of the electrolytic Cu foil production drum is about 10 mm or less, the plate thickness after finish rolling is set to 7, 8, 9, 10 mm, and the plate thickness of the rough rolled material is set to 19 to 70 mm. The reduction rate was secured.

  In any prototype material of the present invention, A / B indicating accumulation in the normal direction of the c-axis plate surface is 3.0 or more in any surface of 1 mm below the surface and 1/2 plate thickness part. The crystal grain size was 8.2 or more, and the Vickers hardness was 115 or more and 145 or less. Further, the occurrence of wrinkling when PVA polishing 1 mm below the surface is “nearly none” or “small”, and the titanium material for an electrolytic Cu foil production drum in which the generation of micro defects due to wrinkles is suppressed. Could be manufactured.

  In Table 2, No. Using the sample of No. 3, the thickness is changed, and the surface of 0.5 mm, 2 mm, 3 mm, and 4 mm below the surface is polished by the method described above, and A / B, crystal grain size, and hardness are polished on each surface. evaluated. As a result, in terms of each thickness, A / B, crystal grain size, and hardness almost coincided within the range of measurement error.

  On the other hand, the heating temperature at the time of rough rolling shifted from 800 ° C. and the α + β temperature range to the low temperature side, and was a temperature range of α single phase. In No. 15, the grain growth during rough rolling was insufficiently suppressed, the crystal grain size of the final annealed material was as low as 7.7, the Vickers hardness was slightly low at around 110, and the wrinkling during polishing was also somewhat high. Moreover, the heating temperature at the time of rough rolling shifted from 920 ° C. and the α + β temperature range to the high temperature side, and was a temperature range of β single phase. In No. 16, the grain growth was remarkable during rough rolling, the crystal grain size of the final annealed material was as low as around 7.3, the Vickers hardness was low at less than 110, and the wrinkling during polishing was somewhat high.

No. in which the starting temperature of finish rolling is higher than 700 ° C. In No. 17, the A / B at the 1/2 plate thickness portion was small, the crystal grain size was low, and further, there was a little amount of wrinkling during PVA polishing. No. with low rolling reduction of finish rolling In No. 18, the A / B was small at 1 mm below the surface and 1/2 plate thickness, the texture was not sufficiently developed, the crystal grain size was low, the hardness was low, and there was a little amount of wrinkling during PVA polishing. No. with low finish rolling temperature No. 19, the deformation resistance was large and rolling was difficult, the plate shape was poor, and the hardness was large and PVA polishing was difficult. No. without Cu addition. In No. 20, the texture was not sufficiently developed, the crystal grain size and hardness were low, and there was a little amount of wrinkling during polishing. In addition, No. with less Cu addition. 21 also had similar results. No. with a large amount of Cu addition. In No. 22, the segregation of Cu was large, the precipitation of Ti ₂ Cu was large, and the macro uneven pattern was generated.

  Moreover, No. using the 1-8, 1-9, 1-10 material of Table 1 whose Cu content was outside the scope of the present invention. About 20-22, even if it manufactures on the manufacturing conditions of this invention, neither crystal grain size and / or A / B satisfy | fills the conditions of this invention, and there are many wrinkles at the time of grinding | polishing, Cu foil A titanium alloy plate suitable for a production drum could not be obtained.

  No. containing 0.08% of Fe above the upper limit. 1-11 material, No.1. A plate with a thickness of 9 mm was produced by the same process as No. 5, processed into a drum shape, immersed in an electrolyte solution, and Fe was concentrated at the grain boundary. Therefore, the grain boundary dissolved preferentially and became a dent. Macro uneven pattern occurred. In addition, No. containing 0.15% or more of oxygen above the upper limit. 1-12 is No.1. When a plate having a thickness of 9 mm was produced by the same process as in No. 5 and processed into a drum shape, a macro non-uniform pattern was generated due to residual stress entered during the processing. No. 1-13 containing 0.010% of hydrogen above the upper limit When a plate having a thickness of 9 mm was produced by the same process as in No. 5 and the plate was cut to be processed into a drum shape, the cut portion was cracked, making it impossible to process the drum.

Claims (2)

% By mass
Cu: 0.3 to 1.1%
Fe: 0.04% or less,
Oxygen: 0.1% or less Hydrogen: 0.006% or less, comprising the balance titanium and inevitable impurities,
1.0 mm below the surface and a portion parallel to the plate surface of the 1/2 plate thickness part, the average grain size is 8.2 or more, and the Vickers hardness is 115 or more and 145 or less,
When the final rolling direction RD, the normal line ND of the rolled surface, the rolling width direction TD, and the normal line of the (0001) plane as the c-axis, parallel to the plate surface of 1.0 mm below the surface and 1/2 plate thickness part In the region, the texture is α phase (0001) plane pole figure from the normal direction from the rolling surface, and the inclination angle of the c axis is ± 45 ° in the TD direction in the wolf net centering on the ND axis. Is the major axis and A is the total area of the crystal grains existing within an elliptical range with ± 25 ° as the minor axis in the RD direction, and B is the total area of the other crystal grains. A titanium plate for an electrolytic Cu foil production drum, wherein the titanium plate is 0 or more.   A manufacturing method for obtaining a titanium material by finish rolling through a hot rolling process by α + β two-phase region heating, wherein the rolling start temperature of the titanium material is 200 ° C. or more and 700 ° C. or less, and the titanium material The method for producing a titanium plate for an electrolytic Cu foil production drum according to claim 1, wherein the steel sheet is rolled at a rolling reduction of 40% or more, and finally heat-treated at 550 to 700 ° C for 10 to 30 minutes.